The announcement on Thursday was one of the last big climate plans from a rapidly-developing economy to be unveiled ahead of a summit in Paris in December aimed at limiting warming to 2C.

Indonesia said it was prepared to cut emissions by 41% from a ‘business as usual trajectory’ if it received financial and technological support from industrialised countries. Jakarta put the price tag on that support at $6bn (£4bn).

But the World Resources Institute (WRI), a leading environmental thinktank, said it was near-impossible to judge the scale of Indonesia’s ambition or how it would actually meet those goals because the country was so vague in its plan.

“It doesn’t include a lot of information,” said Taryn Fransen, who leads the Open Climate network at WRI. “The current version does not allow for any accountability because it is simply not transparent enough.”

Most developing countries have been more forthcoming about what they mean by a “business as usual” scenario, she said.

Indonesia’s plan also set a relatively low bar for moving from fossil fuel to cleaner energy sources, setting a target of just 23% of energy coming from renewable sources by 2030.

Indonesia, a coal producer, has also been leaning more heavily on coal for energy generation, after China drastically cut imports. Coal shipments to China have fallen by close to 50%, according to Greenpeace, while local coal use doubled in the six years ending in 2014. Coal now makes up about 35% of domestic electricity, according to Greenpeace.

Indonesia’s promise before Paris lagged behind other developing countries such as Mexico and South Korea, which have been clear about spelling out their emissions reductions targets to the UN.

So far, only three other countries have been as hazy about spelling out their business as usual scenarios and they are all much smaller than Indonesia: Benin, Gabon, and Trinidad and Tobago.

Indonesia committed four years ago to stop opening up new forests and peatlands for plantation expansion – but huge swathes of forest are cut down and burnt each summer to clear land for corporate development or oil palm plantations.

WRI said Indonesia needed a ban on all future forest clearance, including licences that were awarded some years ago, and have yet to be activated.

“If Indonesia wanted to seriously protect its land and reduce carbon emissions than it needs a permanent moratorium,” said Andhyta Utami, a research analyst at WRI in Jakarta.

Indonesia’s vast swathes of forests and peatlands are one of the most important carbon stores. When these are cut down, or drained and burned, to make way for plantations, carbon dioxide is released.